For example, each of conventional slot machines disposed in a slot machine dome has an internal hopper through which coins are dispensed, entered coins are accepted, or coins paid out to a customer are accepted for circulation.
However, the capacity of the internal hopper is limited from the viewpoint of the size of the slot machine. Thus, if the customer has coins for himself or herself, the coins in the slot machine may increase. Also, the customer may take home coins that are paid out, in which case the number of coins in the slot machine decreases. When the coins in the slot machine increase or decrease substantially, the slot machine must be stopped in order to take out coins from the internal hopper or replenish the internal hopper with coins. This job causes personnel in the gaming house a lot of trouble and is inconvenient to the customer. Moreover the availability of the slot machine deteriorates.